Array antennas are used for a variety of different applications. Array antennas may be constructed using a plurality of notch antenna elements. The term “notch antenna” is intended to include tapered and flared elements, such that the shape is not limited by this disclosure. Each notch antenna element includes an electrically conductive body, referred to as a notch radiator element, which has a slot. The slot separates the notch radiator element into two prongs. One of the prongs may be grounded while the other prong is energized by an RF signal. In general, the energized prong conveys energy from a coaxial feed input into free space or air, or visa-versa. The coaxial transmission line has a characteristic impedance relative to the system impedance for maximum power transfer. The propagating signal leaving the coaxial transmission line, transitions to a tuned gap between the energized prong and the housing. This gap is optimized with other dimensions to result in wideband operation. The unbalanced coaxial transmission line meets the balun at the gap, launching the energy into the notch slot and then into free space or air. The RF signal source is typically embedded in or below the surface of a dielectric substrate and extends below the feed end of the energized prong to couple the RF signal to the notch antenna.
These notch antennas may be combined to form ultra-wideband array systems. Ultra-wideband low loss phased array systems are desired in the cellular, telemetry and military applications. Use of this technology in these areas allow greater flexibility in achieving compact low cost higher power designs.
However, since, in this type of array, the RF signal is traditionally conducted through a PCB trace, conducted power is limited.
In other words, the substrate used to hold the notch antennas, which is typically a printed circuit board, is also typically used to carry the RF signal to the notch antennas. The use of dielectric materials, such as traditional PC boards, as the substrate has certain drawbacks.
Therefore, it would be beneficial if there were a system for supporting the notch antenna elements and transmitting the requisite RF signals without being limited in its power capacity. Further, it would be advantageous if this system was also cost effective, robust and less complex to manufacture.